What is the legal burden of proving the validity of a testamentary document?

When the validity of a testamentary document is challenged, the propounder of the document has a legal burden with respect to due execution, knowledge and approval, and testamentary capacity. Upon proof that the document was duly executed with the requisite formalities after having been read over to or by the testator who appeared to understand it, it will generally be presumed the testator knew and approved the contents and had the necessary testamentary capacity. Where suspicious circumstances are present, then the presumption is spent and the propounder of the document resumes the legal burden of proving knowledge and approval. If the suspicious circumstances relate to the mental capacity, the propounder also reassumes the legal burden of establishing testamentary capacity. These must both be proved in accordance with the civil standard. The burden of proof with respect to fraud and undue influence rests upon those attacking the testamentary document. See Vout v. Hay, 1995 CanLII 105 (SCC), [1995] 2 S.C.R. 876 (S.C.C.).